The present invention relates to a device for wrapping a round bale with a wrapping medium and more specifically relates to a device for handling a supply roll of wrapping medium
DE-U1-82 21 610 discloses a large round baler equipped with a netting wrapping apparatus including a container for receiving a netting roll, a brake, a pair of rollers and a cutting device. The container is located on top of the round bale press and receives a supply roll of netting material, with the roll lying against the walls of the container during unwrapping. The brake includes a swiveling yoke, with a crossways-running rod that is pressed by means of a spring onto the entire circumference of the roll. The rollers run opposite one another and can be powered to pull the netting off of the roll and lead it to a baling chamber, and to tension it so that it lies taut around the bale. The wrapped length of netting can be separated from the roll by a cutting device which operates at the end of the wrapping process and works upon the taut netting.
WO-A1-9705767 discloses a large round baler with a netting or sheeting wrapping apparatus, which enables the free ends of the netting or sheeting to be brought into engagement with the harvested matter and thus to be wrapped around the bale, that has a vertically adjustable netting or sheeting wrapping apparatus. The unwound part of the netting or sheeting is separated from the roll by braking the roll or actually bringing it to a stop, so that the netting or sheeting tears off. How a possible brake could look or might be attached is not disclosed.
According to U.S. Pat. No. 4,956,968 a large round baler is equipped with a netting wrapping apparatus that brings the ends of the netting into the area between the press elements and the round bales by means of a swiveling feed arm. No brake operates on the netting roll itself.
This state of the art yields different types of brakesxe2x80x94those, for one, that are supposed to prevent the wrapping medium on the roll from unwinding, so that the wrapping medium does not build up, as well as those that delay movement of the wrapping medium, so that it is wrapped firmly around the bale and tears off or can be cut easily.
The problem, on which this invention is based, is perceived to be that the aforementioned brakes/rollers, and the balers equipped with them, are relatively complicated.
According to the present invention, there is provided an improved manner of handling a supply roll of bale wrapping medium on a baler equipped with a bale wrapping arrangement.
An object of the invention is to provide a wrapping arrangement for a large round baler including a motor for applying a braking force to a supply roll of wrapping medium during the time that a length of wrapping material is being pulled from the supply roll by the action of a rotating bale located in the baling chamber.
A more specific object of the invention is to provide a wrapping arrangement, as set forth in the previous object, wherein the motor is controlled so as to vary the braking force, and/or duration thereof, applied to a wrapping material supply roll in accordance with atmospheric conditions and/or control signals generated by sensors measuring the quantity of netting or sheeting pulled off the supply roll, the roll-off speed, and the like. The brake includes a contact element mounted at the end of a pivotal arm and, since the position of the arm is indicative of the roll diameter, the quantity of wrapping medium remaining on the roll is a function of arm position and this can be sensed. Also, the contact element is the form of a roller so that its rotation is indicative of the amount of wrapping material pulled off the supply roll, and this rotation can be sensed.
Another broad object of the invention is to provide a wrapping arrangement which, without the need for driven wrapping medium feed rolls, selectively places the free end of the wrapping medium in a position to be grabbed and pulled off the supply roll by the bale-forming elements and/or the formed bale.
A further specific object of the invention is to provide a wrapping arrangement wherein the container for the supply roll and a guide for the wrapping material may be selectively moved between a standby position, wherein the guide holds a free end of the wrapping medium at a location spaced from the baling chamber, and a dispensing position, wherein the free end of the wrapping medium is disposed for being grabbed by harvested matter entering the baling chamber and/or by the bale forming elements and/or the formed bale.
These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings.